Electropneumatic brake.



UNITED STATES PATENT OFFICE.

EDWARD H. DEWSON, 0F NEW YORK, N. Y., ASSIGNOR TO THE WESTINGHOUSE AIR SYLVANIA.

PENN- ELECTR/OPNEUMATIC BRAKE.

Specification of Letters Iatent.

Patented June 20, 1916.

Application led February 9, 1915. Serial No. 7,208.

To all whom t may concern Be it known that I, EDWARD H. DEWsoN, a citizen of the United States, residing at New York, in the county of New York and State of New York, have invented new and useful Improvements in Electropneumatic Brakes, of which the following is a specification.

This invention relates to automatic train control apparatus, and more particularly -to the type in which the brakes are automatically applied in case the speed of the train exceeds a predetermined limit when passing into a danger zone.

It has been proposed to employ an electroma et device on each car controlled by a train line circuit so as to effect a simul taneous application of the brakes on all the cars of'the'train when the danger conditions require it. In order to avoid delays and tie-ups it is desirable that these electromagnetic devices should be operated on a normally open electric circuit, since with a normally closed circuit, any accidental opening of the circuit would cause the stoppage of the train and would then require the location of the open circuit before the train could proceed again. On the other hand, where a normally open circuit is employed, the derangement of circuit or failure of current on a car would prevent an application Aof the brakes from being obtained, an yis would be particularly undesirable in the case of single car operation.

The principal object of my invention is to provide an automatic train control system normally operated on a Anormally open circuit and an auxiliary control operate/d by a local normally closed circuit.

With an apparatus so designed, the operation of the usual trip on the head car would cause a simultaneous application of the brakes throughout the train under normal conditions by the operation of the normally open circuit system. If, however, the open circuit were interrupted, the brakes would still apply simultaneously on cars ahead of the break, while the brakes would be applied serially on the cars following the .break as fast as their trips passed over the track device, through the operation of the auxiliarycontrol governed by the local normally closed circuit. Furthermore, if there should be a failure of current on all the cars, the brakes would be applied throughout the train.

In the accompanying drawing, the single figure is a diagrammatic view of an automatlc train control apparatus for a car and embodying my invention.

In order to illustrate an application of my mvention in a simple form, an ordinary triple valve device shown, comprising the usual casing 1 hflving piston chamber 2 containing piston 3 and valve chamber 4 containing main slide valve 5 and graduating valve 6. The valve chamber 4 is connected by pipe 7 to auxiliary reservoir 8 and brake cylinder 9 is'connected by pipe 10 to passage 11 which leads to the seat of the main slide valve 5.

For convenient illustration, I have shown the triple valve cap 12 modified to contain the electro-magnetlc application valve dev1ce and the auxiliary controlling means. The application valve device may comprise an electro-magnet 13 having one terminal connected to ground at 14 and the other terminal connected to a speed control train line wire 15. The magnet 13 controls a double beat valve 16, which in the normal position opens communication from the brake pipe 17 through a passage 18 to the triple valve piston chamber 2. In the opposite seating position, the brake pipe connection is closed and communication is opened from piston chamber 2 to a passage 19 leading to the brake cylinder 9, so that in this position fiuid may be vented from the triple valve piston chamber to the brake cylinder to thereby cause the usual operation of the triple valve to effect an application of the brakes, thevpassage 19 having a check valve 20 for preventing back flow of fluid under pressure from the`brake cylinder. A battery or source of current ,train wire 21 is provided and the connection of same to the speed control wire 15 is effected by the operation of a switch 22 which is controlled by a magnet 23.v

The normally closed circuit magnet 23 has one lead connected to the source of current W'ire 21 and the other lead 24 to an insulated contact arm 36 which is adapted to turn on its pivot to a certain position correspending with the speed of the train. When the speed of the train increases, the arm moves upward toward the right and when automatically the speed decreases, the arm moves down` ward toward the right.

Any' suitable mechanism may be provided for moving theI arm 36 according to the speed of the train.` but it is not deemed necessary to show such a device in the drawing, since it forms no part of the present invention.

At the outer end of the arm 36 is mounted 1o aA contact roller 37 adapted to engage the curved edge of a plate 38 having a ground connection 39. The plate 38 is provided with teeth 4() adapted to be engaged by a worm wheel 41 carried by a shaft 42 which is operatively connected with a rotating part of the vehicle, so that the shaft and worm wheel rotate according to the speed of the train. The worm wheel 41 is normally held out of engagement with the teeth 4Q by means of a trip lever 43 engaging a pin 44 carried the shaft 42 and said lever is held in its locking position by a magnet coil 45 .having its circuit wire 46 connected at one end to the battery wire 21 and having two 25 terminals at the other end controlled respectively by switches 25 and 47. The switch 47 is controlled by a trip 26 adapted to engage ay ramp 27 located along the track and when the switch 47 is closed the circuit wire R0 46 is connected to ground at 48. The switch 25 is controlled by a solenoid coil 49 having one terminal connected to the trip 26 and the other terminal to ground at 48.

In operation, if the trip 26 passes onto a ramp 27 which is energized, then current will be supplied through the wire 50 to energize the coil 49 and cause the switch 25 to close the circuit wire 46 so that although the circuit is broken through the switch 47 by the lifting of trip 26,in passing over the ramp 27, the closed circuit will be maintained by the closing of the upper switch 25. It will thus be seen that the coil remains energized and that no action will take place. 45 If a danger condition exists, the ramp 27 will be denerriaed and when the trip 26 engages same, n-fswitch 25 will not be operated, while the switch'47 is lifted so as to break the circuit through wire 46. The solenoid coil 45 is thereupon denergized and permits the spring 51 to trip the lever 43 and thereby allow the worm wheel to move into engagement with the teeth. 40. The curve plate 38 is then moved to the left, at 55 a rate corresponding with the speed of the train. The movement of the arm 36 is so related to the movement of the curve plate 38 that if the speed of the train is below the predetermined safe rate, the roller 37 will remain in engagement with the plate 38 as it moves to the left and no action will take place.

If the speed of the train should exceed the predetermined rate at any time during the 55 movement of the curve 38, their the roller 37 will not move downwardly so as to maintain engagement with the curve 38 and as a consequence, the circuit through wire 24 will be broken and the magnet coil 23 thus de energized.

The denergization of coil 23 permits the switch 22 to close and thus establish a flow of current from the battery wire 21 to the control wire 15, so that all the open circuit magnets 13 throughout the train are simul- 75 taneously energized. This causes the double beatvalve 16 on each car to move so as to close the connection for supplying fluid from the brake pipe 17 to the triple valve piston chamber 2 and also open communicaso tion from said chamber to passage 19 leading to the brake cylinder. Fluid under pressure is thus vented from the piston chamber 2 and the triple valves throughout the train are operated to eect a simultaneous applilcation of the brakes throughout the train.

If for any reason, there should be a failure of current or a. local circuit to the magnet 13 should be deranged, according to one feature of my invention, the double beat 9o valve 16 would still be operated upon movement of the core 32 of magnet 23 by the admission of liuid under pressure from supply pipe 35 to passage 33 through the movement of the double beat valve 31, since luid supplied to passage 33 passes to the face of piston 28 and moves same against the resistance of spring 30 so that the core 29 is operated to shift the double beat valve 16, in the same manner as when operated electrically. However, this action will only take place on a car when the trip 26 passes over the ramp 27 or where the circuit of the magnet 23 is denergized by loss of current. It will thus be seen that if a break in the open circuit occurs, that is to say, the circuit including the magnets 13 the brakes will be applied simultaneously ahead of the break by the energization of the magnets 13 when the trip on the head car passes over a deenergized ramp while on the cars at the rear of the break, the brakes will be applied on each car as fast as the cars pass over the ramp. It there should occur a failure of current at any time in the closed circuit magnets 23, the brakes would be applied by the operation of the double beat valves 31. It will also be seen that since a normally open train line circuit ordinarily takes care of the operation, the advantages of the open circuit system are retained while on the other hand, the employment of a normally closed local circuit on each car renders the system safe for operation in case of loss of current or derangement of circuits.

Having now described my invention, what I claim as new and desirf'el to secure by Letters Patent, is:

1. In an automatic train control apparel tus, the combination with an electrically con- 180 mamma zation to effect the simultaneous operation of said devices throughout the train, of a local normally closed circuit and means operated by the denergization of the local circuit for effecting an application of the brakes on the car.

3. In an automatic train control apparatus, the combination with a car valve device for effecting an application of the brakes and electrically controlled means for operating said device, of a normally open train circuitl and a local normally closed car circuit for controlling said means.

4. n an automatic train control appara tus, the combination with a valve device for effecting an application of the brakes, of means responsive to the energization of a train circuit and the denergization of a local car circuit for effecting the operation of said valve device. y

5. in an automatic train control apparatus, the combination with a valve device for cilfecting an application of the brakes, of valve n2 'ans for effecting the operation of said valve device, a normally denergized magnet for operating said valve means, a uid operated piston for also actuating said valve means, valvular means for controlling tlie fluid pressure on said piston, and a' normally energized magnet for operating said valvular means.

6. In an automatic train control apparatus, the combination with a valve device for effecting an application of the brakes of valve means for effecting the operation ot said valve device, a normally denergized magnet for operating said valve means, a fluid operated piston for also actuating said valve ireans, valvular means for controlling the lluid pressure on said piston, a switch controlling the circuit,of the normally deenergized magnet, and a normally energized magnet for operating said switch and the valvnlar means.

in testimony whereof I have hereunto set my hand.

EDWARD H. DEWSON. Witnesses:

Geo. C. ANTI-ion, CLARENCE D BROWN. 

